Joe, 55, said he is smitten with the baby, Jagger Snow, who was born to Ashlee and husband Evan Ross late last month.
He feels she looks just like her parents, reported Female First.
"Jagger is precious. She's quiet and sweet and she's such a happy baby. She's barely two weeks old. The apple of her papa's eye. She's beautiful. She looks like her mommy and daddy."
Joe and ex-wife Tina were present in the delivery room with Ashlee, 30, and Evan, 26, while she was in labour in Los Angeles.
Ashlee also has six-year-old son Bronx with ex-husband Pete Wentz.